We wouldn’t describe NCIS: Los Angeles’s G. Callen (Chris O’Donnell) as a Grinch, but we wouldn’t call him merry either. Last Christmas, the agent’s only holiday decoration was a card from a criminal he sent to the slammer.

This year things are different. On the December 18 episode of the CBS hit, Callen’s smiling over eggnog at the office Christmas party, and he invites love interest Anna (Bar Paly, above, with O’Donnell and LL Cool J) to his home for a Yuletide dinner with his dad, Garrison (Daniel J. Travanti). Just don’t expect mistletoe to become wedding bells.

“In their lives, a happy, healthy relationship is unlikely,” O’Donnell says, “but that doesn’t stop him from being interested.”